Raven down! Mechanical failure :(

[dsgerbc]

Originally Posted by TheRipler

I'm the guy wondering "Why isn't anyone questioning the untuned CAI?", known killers of subaru motors.

Known killer of subaru turbo motors.

[TheRipler]

Originally Posted by dsgerbc

Known killer of subaru turbo motors.

If you think about why that is, along with the difference in compression of these motors and other NA Subaru motors, it should be apparent why it may be an issue. The people who just slap on CAIs are probably not running wide-band O2 sensors, and keeping an eye on things.

Everything I've seen people say here is about the car running rich with a CAI, which was never the issue. It is when the car randomly runs lean under load that kills a motor with detonation or high combustion temps. High compression NA motors can be just as finicky as a turbo when it comes to det. It doesn't really matter if the high compression is dynamic (turbo) or static (NA).

/ot

Still going with oil.

[dsgerbc]

Originally Posted by TheRipler

...
/ot

Still going with oil.

In general I'd agree that some oiling fluke is more likely, with the whole thing being an isolated case.

On the OT: while this car still has MAF in the intake, with similar potential for mis-measurement of the airflow, I think that on turbo-subies un-tuned for intakes were mostly magnifying issues with non-stock maps rather than making oem tunes go crazy-knocking. So I'd doubt that a properly installed quality intake would create issues on an otherwise stock FA20. Now, there could've been a post-MAF leak that is never a good thing.

[fistpoint]

Originally Posted by Lonewolf

How long before this incident did you have an oil change?

Like others have said, improper oil level (way too much or too little) could have caused a problem. (That's why I always check the level after a change)

OR...the person doing the oil change didn't tighten the oil drain plug enough, it worked its way loose, and blamo........!

I had a plug fall out a few days after an oil change on my Acura. The car had right around 35k miles on it, now it has just over 160k and still driving great.

If you pull over soon enough and stop the engine, no damage should be done. In my case I drove almost 3 miles before I realized what the "thunk" I heard actually was. The second I heard a metal on metal grind is when it became obvious to shut the car off immediately. After it was parked you could see almost 2 quarts drain out onto the street. That is what saved the engine.

Got a free 30k service and 8 free oil changes out of it.

[Draco-REX]

Originally Posted by Dimman

Balance has little to do with the failure causes. An L6 is naturally balanced. The problem is resonance which is affected by all the noted differences between the FA and the EJ. True that short crank H4's will have different frequencies than long crank L6, but there are still differences between motors.

An L6 is not natrually balanced. The pistons all fire in the same direction. And as mentioned a couple posts down, an H4 crank is a fraction of the length of a L6 crank. So there's less chance of a damaging harmonic occurring in an H4 crank.

Though I agree that Perrin's R&D is sorely lacking and often fraught with error. That's why I won't put a Perrin product on my car.

I doubt the non-damped pulley was the issue. The untuned CAI is a possibility, however a lean condition usually doesn't cause such a catastrophic failure.

I'm thinking either oil pickup or oil pump failure leading to a rod punching through the side of the block.

[Dimman]

Originally Posted by Draco-REX

An L6 is not natrually balanced. The pistons all fire in the same direction. And as mentioned a couple posts down, an H4 crank is a fraction of the length of a L6 crank. So there's less chance of a damaging harmonic occurring in an H4 crank.

Though I agree that Perrin's R&D is sorely lacking and often fraught with error. That's why I won't put a Perrin product on my car.



I doubt the non-damped pulley was the issue. The untuned CAI is a possibility, however a lean condition usually doesn't cause such a catastrophic failure.

I'm thinking either oil pickup or oil pump failure leading to a rod punching through the side of the block.

L6, V12 and H6 are the only engines with natural primary and secondary balance afaik. H4 has primary but not secondary balance. The forces 'rock' it back and forth.

Either way, we still don't know, and my post was more to throw a little more sense into the people automatically exonerating the pulley. For reference, the ATI damper on my 7M (83x91 BxS) is different than the ATI damper on a 2JZ (86x86).

It would be really nice to get a definitive answer on the cause from Toyota.

[Tugboat]

Originally Posted by dwx

The powertrain (engine) warranty at least on the Subaru side is 5 years, 60K miles.

I understand that, but if someone does go 60k+ miles on this engine before it goes bad? Its going to be on them. I understand that not all cars will last forever. I love my car and will get everything done under warranty that they let me, but until they really find out what's causing some engines to have major problems, I am going to always be worried about taking my car on long trips. Just going to work is going to be a worry some days.

[draggin_az]

did the dealership say anything yet?

[Rayme]

Originally Posted by Tugboat

I understand that, but if someone does go 60k+ miles on this engine before it goes bad? Its going to be on them. I understand that not all cars will last forever. I love my car and will get everything done under warranty that they let me, but until they really find out what's causing some engines to have major problems, I am going to always be worried about taking my car on long trips. Just going to work is going to be a worry some days.

Don't stress because of that ONE accident! I've been driving old cars forever and only been stranded twice by celica's, one had a water pump failure because it was neglected and the other one the pickup coil failed @ 250 000 KM

[rice_classic]

Being at the race track for several years I've failed several engines myself and been around many many others.

I've melted pistons, crack ring lands, blown head gaskets, dropped valves, detonated half-dollar size holes in pistons etc and in none of those incidents did I see anything come out the block. On the melted piston and cracked ring land the pressure in the crank case pumped a lot of oil into my catch tank but that's not what happened here. In the instances where the moving bits actually caused an oil leak it was usually "friction" related where a part that should be protected from friction wasn't and usually has to do with the crankshaft.

I'm going to err on the side of others here and agree that oiling (or lack thereof) played a part in this failure.

[TRBO2NR]

Very true! In the Supra community, undampened lightweight pulleys are one of the biggest known (or suspected) causes of crank walk... I personally plan to avoid this as an upgrade as I don't want to risk adding to the known problems of this car. It MAY be a fine upgrade, but to me it is not worth the doubt to gain a few ponies...

Originally Posted by Dimman

Why are people automatically saying it's not the pulley?

On straight 6 motors, that is pretty much a guaranteed way of destroying your motor. Dampers are the way to go with them.

Perrin has extensive testing of these undamped pulleys on completely different motors. Strokes are different, piston weights are different, cranks are different, vibration will be different. But undamped pulley is the same.

Don't be too quick to dismiss it.

[RossGA]

Originally Posted by ahausheer

Under driven pulleys are completely different as they make things spin faster than they were designed. Also this engine is robust as witnessed by 4 and 5 hundred hp on stock internals lasting for at least a few hundred dyno pulls. A non dampened pulley should not cause acute engine failure in a short period of time on a flat engine. I would expect a longer term degradation to crank bearings if anything.

No, underdrive pulleys spin your accessories SLOWER than they were designed, therefor freeing up power. You can typically get away with this as auto OEMs spin things at an aggressive rate so you get full Alt charge and good AC at a low idle. More underdrive = more power freed up and now available to hit the pavement. Also means more chances of not having cold AC at idle, and annoyances like dimming headlights at traffic lights.

But the aftermarket pulleys that I have seen for the 86 are not "underdrive". They are just "light-weight". Light weight pulleys just reduce rotating mass, without changing the speed of anything on the accy belt.

Either way, they are not dampened, although it is a stretch to call the stock pulley's thin band of rubber out towards the outer diameter of the pulley an effective dampener. That is most likely there to take some engine pulsing shock off the belt more than anything else. If it is a dampener, then they were seriously trying to save some money.

[rice_classic]

Originally Posted by TRBO2NR

Very true! In the Supra community, undampened lightweight pulleys are one of the biggest known (or suspected) causes of crank walk... I personally plan to avoid this as an upgrade as I don't want to risk adding to the known problems of this car. It MAY be a fine upgrade, but to me it is not worth the doubt to gain a few ponies...

Add Honda's to the list. Several Honda owners have experienced crank-based failures that they attributed to removing the harmonic balancer and replacing it with light pulley or under-drive pulley.

[SpeedR]

Originally Posted by ahausheer

Under driven pulleys are completely different as they make things spin faster than they were designed. Also this engine is robust as witnessed by 4 and 5 hundred hp on stock internals lasting for at least a few hundred dyno pulls. A non dampened pulley should not cause acute engine failure in a short period of time on a flat engine. I would expect a longer term degradation to crank bearings if anything.

You dont know what your talking about...